The rapid development of multimedia society mostly benefits from the tremendous progress in semiconductor devices or display devices. Among the display devices, LCDs having superior characteristics of high definition, great space utilization, low power consumption, and non-radiation have gradually become mainstream products in the market.
To date, the liquid crystal displays (LCDs) with high contrast ratio, no gray scale inversion, low color shift, high luminance, full color, high color saturation, high responsive speed, and wide viewing angles are required on the market. In order to provide the wide viewing angles, some displays, such as twisted nematic (TN) liquid crystals with wide-viewing films, in-plane switching (IPS) LCDs, fringe field switching (FFS) LCDs, and multi-domain vertically alignment (MVA) LCDs, have been developed.
However, when producing TN LCDs, two alignment layers are required to align liquid crystal molecules in the liquid crystal layer, which takes longer processing time and costs more. Besides, TN LCDs have disadvantages such as asymmetrical viewing angles, higher luminance in the dark state and lower contrast. Disadvantages such as lower light transmittance, lower responsive speed and higher color shift exist in vertically alignment LCDs.